1. Field of the Invention
This invention relates to an apparatus for processing sensitive materials in which sensitive material such as exposed film is conveyed through a vessel filled with a processing solution by a plurality of conveying rollers, to be subjected to the processing, and more particularly to an apparatus for processing sensitive materials in which the conveying rollers are kept free of any sticky materials that may tend to attach to the roller surfaces.
2. Description of Prior Art
In the processing of a sensitive material, such as in a process for developing a film, it is often the case that when halogenated silver particles having a latent image core on a film surface are converted to metal silver by chemical reaction a part thereof separates from the film surface and sticks to the surfaces of conveying rollers, thereby causing a so-called silver stain. As the amount of such metal silver stuck to the surfaces of conveying rollers is gradually increased, the silver is transferred from the surfaces of conveying rollers to the film conveyed by the rollers, resulting in the film being stained.
Furthermore, in a film-washing process, it is often the case that the surfaces of conveying rollers are stained by deposits and/or gelatin on the film surface, and this adversely affects the film conveying process.
In order to overcome such problems, it is necessary for a large number of conveying rollers together with a side plate on which the conveying rollers are supported to be frequently taken out of the processing solution for cleaning. Such taking out and cleaning is not easy, particularly in the case of a large-sized processing apparatus.
In order to solve the foregoing problem, an apparatus has been already proposed by the applicant, as disclosed in Japanese Utility Model Publication (unexamined) Sho 58-135743, wherein conveying rollers are automatically cleaned by washing rollers which are pressed on the conveying rollers and rotated so that their contact surfaces on one side are opposite to one another. This known apparatus is indeed useful for cleaning the rollers, but the processing unit becomes complicated in its entirety, and moreover it is troublesome to clean these washing rollers which themselves become stained in cleaning the conveying rollers.
Another apparatus for reducing the sticking of silver transferred from the conveyer roller surfaces, by forming spiral grooves on the conveying rollers, has been also conventionally used. But this apparatus is not very useful when carrying out processing over a long period of time.